System for the treatment



T. R. A. KOCHER.

SYSTEM FOR THE TREATMENT OF CELLULOSE OR THE LIKE.

APPLICATION FILED FEB- 21, 1917.

1362,875, I I Patented Dec-21,1920.

W 4% W M A TTORNEY UNITED STATES PATENT OFFICE.

RUDOLPH A. KOCHER, or SAN rnnivcrseo, CALIFORNIA,

SYSTEM FOR THE TREATMENT OF GELLULOSE OR THE LIKE.

1,3easv5.

To all w/e om it may concern:

Be it known that I, RUDOLPH A. KooHnn, citizen of the United States, andresident of San Francisco, in the county of San Francisco and State ofCalifornia, have invented certain new and useful Improvements in Systemsfor the Treatment of Cellulose or the like, of which the following is aspecification.

My invention relates to improvements 1n systems for the treatment ofcellulose or the like and is particularly adapted for the treatment ofcellulose with a hydrolyz ng agent or agents for the purpose of changingthe cellulose into other products, for example, glucose, which may thenbe fermented to produce alcohol. The object of the invention is toprovide a system in which not only may the cellulose material be treatedquickly, effectively and efficiently,

but also in which the treating materials may be eflicicntly generatedand stored and effectively recovered for continued use.

Further and more specific -objects, features and advantages will moreclearly appear from the detailed description given below, taken inconnection with the accompanying drawing, which forms a part of thisspecification and illustrates more or less diagrammatically a systemembodying the invention in one form.

Referring to the drawing, 1 represents a treatment container, comprisinga horizontal cylinder provided with an external jacket 2, into whichwater may be introduced through a pipe 3 and taken off through a pipe 4for the purpose of cooling the contents of the container 1.

If it is desired to heat the container and the contents therein, thewater valves 5 and 6 are closed and steam is admitted through the pipe 7by opening valve 8. The steam may be conducted from the jacket through apipe 9 by opening the valve 10. If the container 1 be large, internalheating means may be provided centrally located within the container 1.I have shown for this purpose a hollow shaft 11, which hollow shaft isjournaled at each end of the container and carries on one end a gear 12,meshing with a gear 13, which is driven by a belt from any suitablesource of power. A. steam connection may be made with the hollow shaft11, so that steam may be introduced thereinto for the purpose of heatingthe material in the middle of the container 1.

Specification of Letters Patent. Pat t d D 21 1 Application fi1edFebruary 27, 1917.

serial No. 151,175.

The shaft 11 carries four spirally arranged agitating blades orscrapers, 14 and 15, only two of which are shown, the other two belnglocated diametrically opposite the two shown. The blade 14 tends to movethe material in the container 1 in one direction horizontally of thecontainer, while the blade 15 moves the material in the other direction,so that during treatment, these blades move the material being treatedback and forth horizontally of the cylinder 1. After the treatment iscompleted, an outlet 16 may be opened in the bottom of the container andas the material is moved back and forth, it will be delivered to theoutlet at 16 and deposited in any suitable container, which may beplaced beneath the outlet.

The material is introduced into the container through a manhole 17 asfrom a hopper 18.

The system may be effectively used for carrying out the processesdescribed in my applications, Ser. No. 65676, filed Dec. 8, 1915, Ser.No. 130563 filed Nov. 10, 1916 and Ser. No. 132584 filed Nov. 21, 1916,in which the treatment of wood cellulose with hydrochloric acid of atleast 39% strength, under certain conditions of pressure andtemperature, to hydrolyze cellulose to glucose, is described.

lVhile the system is suitable for the use of various treatin agents, itis more particularly adapted to the use of a halogen acid for thetreatment of cellulose, and in particular, hydrochloric acid. Thecellulose is treated with hydrochloric acid of at least 39% strength inorder to bring about the desired conversion, and in order that this acidmay be easily and effectively recovered, only a small amount of liquidacid is used. I preferably use only from 4:0 to of water in the liquidacid based on the weight of thecellulose material. In order that thetreating acid may be kept to the desired strength, even although thetemperature is somewhat raised to hasten the conversion, 1 provide meansfor introducing the gas of halogen acid, as, for example, HCl gas intothe container under pressure after the air has been withdrawn therefrom.

The hydrochloric acid gas may be stored under pressure in a tank 20 orother storage means, and leading from the tank 20 is a pipe 21, throughwhich the hydrochloric acid gas may be introduced into the container 1by opening the valves 22, 23 and If the gas within the tank is not undersuflicient head of pressure to introduce the gas into the container 1under sufiicient pressure, the valve 22 may be closed and the valve 25opened and the force pump 26 set into operation, so that the pump 26will force the gas into the container 1 under sufficient head ofpressure. In order to determine the pressure at any time, the container1 is provided with a recording pressure gage 27.

The treating of the material in the tank with the hydrochloric acid gascauses the temperature to be raised, and in order that the same may notbe raised beyond the desired point, a recording thermometer 28 isprovided for indicating the temperature within the container 1, and incase the temperature tends to rise above the desired point, coolingwater or brine may be introduced through the pipe 3 into the jacket ofthe container to maintain the temperature at the desired value. Afterthe conversion has taken place, the hydrochloric acid gas may be removedfrom the containerand recovered for further use.

For this purpose, I provide in the system an air-tight container 29,containing diluted hydrochloric acid, down to the bottom of whichextends a pipe 30, connected with the main pipe 21, leading to thecontainer 1, through a valve 31. Leading from the container 29 to awater cooled condenser 32 is a pipe 33 provided with a valve 34.. Thecondenser 31 is provided with pipes 35 connected to headers 36 and 37,pipes 35 being cooled by the surrounding cold water in the condenser,which water may be introduced through a pipe 38 and which may leave thecondenser through apipe39.

Connected to the header 37 is a pipe 40, which leads to a scrubber orair-tight tank 41 containing pieces of pumice stone and sulfuric acidfor the purpose of thoroughly drying the gas passed therethrough. Thepipe 40 extends to the bottom of the scrub ber 41 and is provided with avalve 42, The acid in the scrubber 41 may be renewed or removed throughthe pipe 43. A pipe leads from the top of the scrubber 41 through avalved pipe 45 to an exhaust or evacuating pump 46. The other side ofthe pump 46 is connected to a pipe 47, which in turn is connected to apipe 48 leading to the external atmosphere, the pipe 48 being providedwith a valve 49. Pipe 47 is provided with a valve 50 and leads to theforce or pressure pump 26. In the pipe connection between the pressurepump 26 and the main pipe 21, there is provided a pressure chamber 51 ofany suitable kind, and if desired a check valve may be placed in theupper part of pipe 21. to prevent any back flow of gas from thecontainer 1 toward the tank when the gases in the container 1 a1e"'underpressure, and likewise a check valve may be placed in the pipe 30, sothat when the container 1 is being evacuated, there will be no back flowof gases or vapors into the container 1.

In operation, after the conversion has been carried out to the desiredextent, the valve being closed and the valve 24 open, the valve 31 isopened and the gas within the container 1 being under pressure,immediately passes into the tank 29, Where any solid foreign particlesor solid matter may be taken up bythe dilute hydrochloric acid, afterwhich the gas passes through the pipe to the condenser 32, in'whichpractically all of the hyrochloric acid solution in the gas is condensedto form liquid hydrochloric acid solution which is collected in theheader 36. From the condenser 32, the gas passes in the scrubber 41,where it is thoroughly dried and purified.

From the scrubber 41, the gas passes through pipe 44 and assuming theexhaust pump valve 52 to be closed and the valve 53 in by-pass about thepump 46 to be open, the gas will pass directly to the pipe 47 and if itis not desired to save the same, it may be. allowed to escape to theatmosphere through the pipe 48, the valve 50 being closed. As it isgenerally desirable, hoW- ever, to save this purified hydrochloric acidgas for further use, it is preferably conducted to the pressure pump 26by closing valve 49 and opening valve 50, which pressure pump will forcethe gas under pressure into the storing means 20, so that it may againbe used for treatment of material.

latter as much of the gas in the container 1 as will come oil withoutevacuation has been removed in this manner, the valve 53 is closed, thevalve 52 is opened and the exhaust pump 46 put in operation to remove asmuch of the gaseous matteras possible from the container 1. If thetemperature of the container be properly adjusted, not only will all ofthe hydrochloric acid gas be given ofi from the container 1., but 'HGlgas will begiven off from the liquid hydrochloric acid present inthematerial until the strength of liquidacid inthe material is reduced toabout 20% and then if the temperature of the material be at the properpoint, even a large amount of this liquid hydro- :hloric acid of about20% strength, may 0e vaporized and so withdrawn from the material in thecontainer 1. This liquid hyro- :hloric acid will be condensed in theconlenser 32 and so saved for further use.

When a new charge of cellulose material has been introduced into thecontainer, this hydrochloric acid condensed in the header 36 may be usedto supply the necessary amount of water to the new charge in thecontainer by opening valve 53 in the pipe 54 leading from the bottom ofthe header 36 to the pipe 21, which leads to the container 1. Likewise,the dilute hydrochloric acid in the container 29, after it has beencharged as far as desirable with foreign matter, such as wood parts,etc., drawn off from the container 1 with the gas, may be dischargedinto the container 1 by opening valve 55.

In order that any loss of hydrochloric acid gas may be promptly andefiiciently replenished to the system, 1 provide a gas generator at 60of any suitable kind, from which a pipe (51 leads to the header 36 ofthe condenser 32, the pipe 61 being provided with a valve 62. When it isdesired to replenish gas tothe system, the generator 60 is put inoperation and as the gas is generated,

that l r v 2 U f,

WNWliltlttllllllllllmdtnw V valve 62 is opened and the pumps and 26 setin operation, so that the gas is drawn through the condenser 32 andscrubber 411 to purify the same and then is forced into the storingapparatus 20 by the force pump 26.

Before charging the hydrochloric acid gas into the container 1, it isdesirable to remove or exhaust most of the air from the container andthis may be done byclosing valve 50 and opening valve i9 and setting theexhaust pump -16 into operation. The air will then be drawn from thecontainer 1 through the pipe 21, the tank 29, condenser 32 and scrubber4:1 by the exhaust pump 16 and discharged therefrom to the atmospherethrough pipe 48. Afterthe air has thus been evacuated from the chamber1, valve 31 may be closed and valves 22 and 23 opened, so that underpressure in the tank 20 may be admitted to the container 1 as firstdescribed.

While I have illustrated only a single treatment container 1, a singletank 29, a single condenser, a single scrubber, a single vacuum pump, asingle force pump and a single storage tank, it is obvious that all ofthese elements as well as others, may be duplicated and operated inseries, that is, the gas obtained from the operation after thetreatment; of the material in the container 1 may be purified asdescribed and then discharged into the storage means for use in a secondcontainer and so on. Likewise, the hydrochloric acid recovered in thecondenser 32 may be used for providing moisture and some of the acidrequired in a second container. Several of such systems may be thusconnected up in series, and, if desired, the last may be connected tothe first so that a cyclic path of operation is provided. In such acase, it is not necessary that the gas recovered from one operation beput into a storage means prior to its being used in a second operation,but it may be forced directly into the second treatment container by theforce pump, which container thus acts as a storage means. In order thatthe amount of evacuation of the container 1 may be easily known, arecording vacuum gage 63 is provided on the container 1.

.In using the system for the treatment of wood cellulose material, suchas sawdust, to produce glucose, I preferably keep the temperaturebetween and 60 C. and the gas is preferably maintained at such apressure as to insure a constant excess of gas above the rate ofabsorption of the gas by the moisture and porous material. I prefer tofeed the gas at such a rate as to maintain a pressure in the converterof from 40 to 60 pounds per square inch. The greater the pressure, thequicker the desired or necessary strength of acid is formed with themoisture or dilute acid already present in the mixture. This strength ofacid should be at least 39% if HCl is used. For con- .venience in actualoperation, I prefer to use approximately saturated acid. The strength ofsaturated acid is, of course, different for different degrees ofpressure and temperature, so that for increases of temperature, as, forexample, 40' to 60 (1, the pressure must be raised at least sufficientto form or maintain an acid of 39% strength. that this pressure is forany given temperature may be easily calculated. The time required tosaturate large quantities of material in the manner indicated variesfrom one-half hour to two hours, depending upon the degree of cooling,amount of agitation and pressure.

There will usually follow a short period during which the materialstands at a temperature of 10 to, 60 C. after the necessary strength ofacid has been reached and during this period of heating at thistemperature, it is not always necessary to agitate the material. Thehigher the temperature used and the greater the strength of acid used,the shorter the time it takes to produce the desired conversion. Theconversion can be carried out at ordinary room temperature, althoughthis takes somewhat longer, and if desired the saturated acid maybeformed at ordinary room temperatures and then later the conversionaccelerated by increasing the temperature of the material. The heatformed during the absorption of the HG]. gas may be used to acceleratethe hydrolysis. As an example, it may be stated from actual experiencethat material which stood in contact with acid of 42% strength hadreached the maximum conversion, after standing for one hour at 40 to 450., in one-half hour at C.

Provided that the treatment is such that the cellulose is not onlyconverted to glucose, but the glucose has to some extent beenreconverted to other materials, then the mass, after being dried out andremoved from the container 1, may be boiled with water to reconvertthese materials to glucose or to similar fermentable products.

The amount. of water added V is generally such as to form about a 30%glucose solution a after this final hydrolysis has taken place. place-inthecontainer 1, the heat being applied by turning steam into the jacket2 of the container, or by turning-steam directly into the interior :oftheichamber or container 1. Or thiszstep mayzbecarried out= ini anautoclave:

Following-this -step,-the material may be further diluted and isready-forfermentation without the necessity of'separating the glucosematerial fromitheiinsoluble residue or lignine. The-amountsof acid:remaining is such asito form'iapproximately a 1%acid solution whenthe:first water is'added to form the 30% glucosesolutionn Itis alsoobvious-'thatainstead ofooperating a nume berof converters andconnecting pieces of apparatuswin series that they may beoperatedsincparallel and if desired, the storage i'tanks -may: all beconnected together.

Likewise, if desired, afterthe conversion of e the material has takenplace in container-l,

it may be discharged into a second container of the system, wherein thehydrochloric acid mayfbe removed therefrom in the manner described, andthen it may be discharged into another container 1, .in which watermaybe added to it .to produce anydesired reconversion;

All parts with which the acid comes in contact'are suitably protected bya coating of acid resisting material.

While I have described myimprovements in great idetailrwithrespect toone embodiment thereof-,1 .do-not desire to be limited to suchdetails-since many changes and modificationsother 'than those mentionedmay bemadewithout departing from the spirit and scope of my invention inits broader aspects.v Hence, it is desired to cover all. systems comingwithin the language of theappended claims.

hat I claim as new and desire to secure by Letters Patent is:

1. A system for the treatment of cellulose or the like, having incombination a treat ment containenmeans for introducing a hydrolizingacid gas into said container'and means for withdrawing said gas fromsaid container andstoring it, and means for condensing a solution of theacid gas from said gas, on its way to be stored.

2. A system-for the treatment of cellulose or the like, having incombination a treatment container, means for introducing a hydrolizingacid gas into said container and. means for withdrawing-said gas fromsaid container and storing it, means for remov ing moisture or Watervapor from said gas on its way to 'be stored, and for removing foreignparticles from said gas on its way to be stored, and for condensing asolution This boiling With-water may take of the acid gas fromsaid gas,on its way to be stored 3. A system for the treatment of cellulose orthe like, comprising a treatment container; withmeans for agitating thematerial therein, meansfor-introducing halogen acid gas into'sa'idcontainer,- means for withdrawing: halogen acid gas from said container'and'storing it under pressure and means forcondensing a solution ofhalogen acid from said gas, on its way to be stored.

Asystem for the treatment of'cellulose orthe like, having in combinationa treatment container, means 'for'storing a gaseous cellulosehydrolyzing agent under pressure, ineansrforcondu'cti-n'g said gas fromsaid storage means and introducing it intosaid container "underpressure, an exhaust pump for withdrawing the gas 'from said containerand a force pump for forcinggas so Withdrawn, into said storing meansunder pres sure.

A system for the-treatment of cellulose or'theilike, havingZlIFCOIIlblIliLtlOIl a treatment container, means :for generating ahalogen acid gas, means for storing said gas, means-forforcing the gasfrom said generating means intosaid storing means-under pressure,'meansfor'conducting the gas from said. storing means to said container, andmeans for Withdrawing the gas from said container and conducting it tosaid forcing means to be forced into said storing means under pressure.

6. A system for the treatment of cellulose or the like, having incombination a treatment container, means for generating a hydrolizingacid gas, means for storing said gas, means for forcing the gas fromsaid generating meansinto said storing means under. pressure, means forconducting'the gas from said storing means to said container, and meansforrwithdrawing the gas from said container and means for removingmoisture from said gas on its Way to the storing means.

7. A system for thetreatment of cellulose or the like, havingincombination a treat ment container, means for generating a halogen acidgas, .means for storing said gas, means for forcing the gas from saidgenerating'means into said storing means under pressure, means forconducting the gas from said storing means to said container, and meansfor withdrawing the gasfrom said container and conducting it, to saidforcing means to be forced into said storing means under pressure, andmeans for removing moisture from'the gas on its way'from the generatingmeans to the storing means and from the gas on its way from thecontainer to the storing means.

8. A system for the treatment of cellulose material or the like,having-in combination a treatment container with means for agitating thematerial therein, means for varying the temperature in said container,means for forcing hydrochloric acid gas into said container underpressure and means for evacuating said container to remove hydrochloricacid gas and hydrochloric acid gas solution from the container.

9. A system for the treatment of cellulose material or the like, havingin combination a treatment container, with means for agitating thematerial therein, means for varying the temperature in said container,means for forcing a hydrolyzing acid gas into said container underpressure and means for evacu' ating said container to remove acid gasand acid gas solution from the container, and means whereby both theacid gas and acid solution may be purified and stored and again returnedto said container.

10. A system for the treatment of cellulose material. or the like,having in combination a treatment container with means for agitating thematerial therein, means for Varying the temperature in said container,means -for forcing halogen acid gas into said container under pressureand means for evacuating said container to remove halogen acid gas andhalogen acid solution from the con tainer, means for separating thehalogen acid solution from the halogen acid gas and means for returningthe halogen acid solution to the treatment of material independently ofthe halogen acid gas.

11. A system for the treatment of cellulose or the like comprising atreatment container, means for introducing an acid gas into thecontainer under pressure, to act upon the cellulose material or the likein the container, means for separating acid gas from the materialtreated and means for condensing a solution of the acid gas so separatedand mixing it with a fresh charge of cellulose or the like to be treatedin said container.

12. A system for the treatment of cellulose or the like comprising atreatment container, means for introducing an acid gas into thecontainer under pressure, to act upon the cellulose material or the likein the container, means for separating acid and acid gas from thetreated material and means for'condensing a solution of the acid gas soseparated and mixing both the acid solution and gas with a fresh chargeof cellulose or the like to be treated in said container.

Si ned at Decatur, in the county of Adams and tate of Indiana, this 22ndday of February A. D. 1917.

RUDOLPH A. KOOHER. lVitnesses:

C. J. LUTZ, FRED B. SMITH.

